Corrugated-metal culvert



Dec.13, 1927. 1 1,652,763

A. S. CUSHMAN CORRUGATED METAL CULVERT Filed June 17. 1926 2 Sheets-Sheet 1 y, 1MM

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N (RWA INVENTOR.

BY I

A TTORNEYS Dec. 13, 1927.

A. s. CUSHMAN CORRUGATED METAL CULVERT Filed June 174 1926 2 Sheets-Sheet 2 IN V EN TOR.

A TTORNEYS Patented Dec. 1,3, 192.7.

UNITED STATES PATENT OFFICE.

ALLERTON s. CUSHMAN, or GREENWICH, CONNECTICUT, iss'IeNoBJ To THE AMERICAN ROLLING MILL COMPANY, or MIDDLETOWN, omo, A' CORPORATION or omo.

CORRUGATED-METAL CULVEBT.

Continuation of application Serial No. 9,021-, filed February 13, 1925. This application tiled .Tune 17, 1926.

Serial No. 116,689.

My invention relates to corrugated metal vculverts which are very widely used for all kkinds of drainage and sewage purposes and this application is a. continuation of my former application Serial No. 9021, filed February 13, 1925. The culverts involved in this invention are made as full circle culverts and of the nestable 'types, from thin light corrugated metal, and the sections are secured together to form a continuous corrugated culvert in a variety of Ways.

These culverts are formed of sheets corrugated and bent into tubular form, the longitudinal edges being secured together by riveting, or otherwise, as desired. The

longer culverts are made up of shorter sections by inserting the sections end to end into telescoping relation and, if desired, further securing them together by rivets, bolts or the like. Two or more of the shorter sections may be secured together at the factory, or elsewhere, and the desired number thus joined shipped to the place of installation where they may be still further secured together end to end to form a culvert of any desired length. Or if desired the Aindividua-l sections may be shipped separate and secured together Where installed, or if its length is not too great the culvert may be shipped complete. The Aparticular procedure followed in this regard will be as desired for the existing conditions.

The corrugated culvert is recognized as taking animportant place in industry due to certain factors thereof which should be noted. The strength -factor imparted by the corrugations permits of the culvert being" vmade of relatively thin metal, and stillable to withstand the great strains incident to the support of fills of earth, heavy traffic, and allow for expansion and contraction under different climatic conditions and other causes.A This makes for inexpensiveness and relatively small weight.

The corrugations lock themselves into the earthof fills, preventing displacement and holding the earth against movement adjacent to the bodies of the culverts,` thus obviating the danger of the 'culvert being Washed out in whole or in part or being disrupted.

The corrugated type of metal culvert lends` itself to a simple and strong lapped joint, by

earth through their entire length and cirv cumference.

The cylindrical, cireumferentially corrugated` culverts withstand great strains tending to Hatten or crush them by giving Way to the weight 'of the earth above (shortening of the vertical diameter) and seeking side support from the earth at the sides (lengthening of horizontal diameter). As shown by recent tests the corrugated culvert tends under the pressure of embankments to take an elliptical shape and the pressures at the top and sides are equalized. This is contrary to the behavior of rigid types of culverts where the culvert must carry the load of the embankment Without material deflection, for here deflection causes fracture and subsequently failure.

Investigations of thousands of culverts in actual service from one to twenty years have shown that the life of the metal culvert of the corrugated type is terminated by the failure of the bottom section of the culvert to resist the effects of abrasion and corrosion. lVhile the culvert sections are Well galvanized asusually produced, it is well known that the galvanized coating, which is aping removing rust iilms as fast as formed and thus hastening the deterioration of the bottom section by a combination of corrosion and erosion. Also where the joints of the sheets whichimake up the culvert sectionsy loo come at the bottom of the culvert when laid,

. made to provide against the unevenness of.

this churning and abrasive action is further accelerated. For this reason the joints are usually set in alternate series at 90 to the vertical median plane of the culvert and on each side thereof. l

The problem presented has 'been recognized in the art, and many efforts have been the bottom of the culvert Where the abrasive action comes. Culverts have been made with round bottoms or inserts free of corrugations, or with perfectly flat bottoms, but

must withstand the strains of expansion., con-" traction and deflection in use without any considerable extra weight, or added pieces, or fragile or brittle structures within the culvert sections.

Furthermore thc necessary function of delection of the culverts, requires that any attempt to prevent the unevenness of the bottom floor of the culvert be accomplished with such material as will not break when this deflection takes place.

One of the objects of my invention is tol provide for corrugated culverts a coating of material having certain essential features, which result in the provision of an adequate, inexpensive and permanent method of maintaining all of the advantages of the cylindrical, circumferentially corrugated culvert,

lincluding resistance to great strains both from without and within, resistance to strains from freezing, and the like, (the culvert being yconstructed to yield slightly under loa-ds before approaching the point of failure), with the additional great advantage of being fully protected against that abrasive action which has heretofore been the only real. drawback to-universal acceptance of Athe devices in question in the place of cast .iron or concrete tiles.

As the resultofl many experiments I pref- .erably employ in my coating a bituminous body having high surface adhesion so that itclings tightly to the culvert surface, a perv inertnesssol that it will substantially resist all chemical andgalvanic action and have such toughness as will withstand the abra'- sive action of sand, pebbles and the like over a long period of time without wearing away or exhibiting fatigue.l

In its physical structure my coating is preferably cut down to a thin layer over the culvert surface except along the base line thereof, when laid. The lcoating at the base line should be applied in sufficient quantities to fill up the corrugations` at the bottom of the culvert, either practically to the apices thereof, or to cover them. It may be considered in some instances advantageous to coat the entire interior or exterior or both, of the culvert with a paint-like-film,

but it will always be desirable in addition to the filling of the corrugations at thel bottom, to coat the inside of the lower portion of the culvert above the filling. However, the ultimate essential is the filling of the corrugations of the culvert along the base line thereof, where the greatest eroding action and wear takes place when the culvert is in use.

Thus in its essence my coating serves as a substantially smooth floor for the culvert lengthwise of the base thereof, with the highly `desirable extension of a film-like coating up the side of the bottom section of4 the structure. The advantages of this are that but little weight is added, and by filling the interior depressions of the corrugations 4vert, or culvert section, or dipping it and holding it substantially horizontal' so that all of the material will flow away which is in excess of that Acovering the sides and filling the interior depressions of the bottom corrugations. Further it adapts' itself for use with materials which are heat plastic and quick setting, such as bituminous materials, which exhibit in their qualities, the required factors, and provide the protection desired without involving any disadvan manent resiliency so that it willneithercctages.

crack nor break when subjected to deflection in use, and which will adhere to the portion of the `culvert tov which it is applied under all of the varying conditions to which the culvert is subjected in use. It must have an.

absence of, brittleiz'less so that it will Withstand rough handling, and a high degree of Another feature of my improved resilient or elastic coating material is that it best resists the abrasive actionof sand, gravel, and the like. This makes possible the use of the highly desirable corrugated culvert without the heretofore 'serious defect of the wearing away of the culvert bottom by abrasion or lll) v:is turned oppositel erosion by sand, gravel and other materials passing therethrough, and without detracting in any way from the numerous advantages possessed by such corrugated culverts.

Further objects, advantages and capabilities will hereafter more fully appear.

My invention further resides in the combination, construction and arrangement of parts illustrated in the accompanying drawings, and While I have shown therein a preferredembodiment I wish-the same to be understood as illustrative only and not as limiting the scope of my invention.

In the drawings:

Figure l is a side elevation, partly in section, of a typical culvert formed of sections riveted together and coupled in lengths.

Figure 2 is a section on the line 2-2`of Figure l.

Figure 3 is a. side elevation of a joining band.

Figure 4 isa perspective of a. section of a culvert section, showing the novel coating and filling applied thereto.

Figure 5 is a fragmentary section taken horizontally through the device shown in Figure 4, and looking down, and on line 5 5 of-Fig. 6.

Figure 6 is a fragmentary section taken vertically through Figure 4.

Shown in Figure 4 is a single culvert section forme-d of a sheet 1 provided with lengthwise corrugations 2, 2a and formed into a corrugatedcylinder, with a lap jointat 3, secured by means of rivets 4. The corrugations are indicated with internal crests marked 2, and external crests marked 2a.

The culvert sections indicated generally at -5 in Figure l, are joined together end to end by omitting a rivet or so at one end of each section, and Aspreading the end of one section so that-it engages over a previous section as indicated by the telescoping or lapped joints at 6 (Figure l). The lap joint 3 of each section, in forming the long culvert to the joint 3 of the section to which it is attached. Rivets 7 set in place around the joints 6 between sections serve to hold them permanently together.

In joining togetherV the culvert sections on the job, I preferably provide the band type of union. This comprises a narrow corru gated cylindrical section 8, having brackets 9 at the ends, through which the tightening bo'lts l0 are passed.

Each culvert section terminates at each end with ant external crest 2a, and the long culvert naturally terminates in the same manner. In joining culverts together they are in some instances butted against each other, and bands are'set over the meeting ends and these bands are then clamped tightly by -means of the bolts. Due to the corrugated structure of the sections and the band, the

culverts are -jkeyed tightly together preferably by the form of union shown.

The sheets can be galvanized before or after being formed into culvert sections, or may be formed into culvert sections, then united into full length-'culverts and finally galvanized, if desired.

Vhen the culvert is of the nes'table type the nestable sections are assembled for use and treated in the same manner as the full i circ'le culverts herein describedand embody-- ing my invention.

The provision of the protective coating is made after the culvert is of full shipping length and hasbeen galvanized. -The coating is preferably applied by means of spraying or dipping, and the culvert held in substantially a. horizontal position during solidification of the material applied to the culvert; however, it may be applied in other ways if desired, Aand either before shipping or on the job.

In the instance of dipping, the culvert is held substantially horizontally and dipped into a trough containing a heat liquefied bituinen, which is ofthe type having a high surface adhesion and resilience, and which when set possesses a sufiicient degreev of eX- pansion and contraction so as to respond to the expansion and contraction of the cylindrical corrugated sections to which it is applied, so as to prevent breakage and separation from the metal, and which vis somewhat -plastic when cold. Other vmaterial as a coating which has like or similar characteristics may be employed.

After the culvert has been dipped as low as desired into the bath of bitumen, it is elevated and held substantiallyr horizontal until the excess has flowed away. Thus on the outside of the culvert\ all but a coating film will flow off, and on the inside all but a coating film will flow down tothe central base line of the culvert, and thence out through the ends thereof. The material will thus fill the interior depressions of the corrugations along the base line of the culvert,

and the culvert will be held in substantially horizontal position at least long enough for the liquid thus collected in the interior depressions of the corrugations to solidify.

In Figure 4 the result is shown graphically. There will thus be a coating or fihn 20 (shown exaggerated in Figure 4), on the outside of the culvert, and on the inside there will be a coating or film 2l (also shown exaggerated), at each side of the base central line, and a substantially smooth floor 22, which substantially fills the interior depression of the corrugations'and covers the internal crests of the corrugations.

In Figure 4 the culvert was only dipped about half way and the coating thus only extends part Way of the finished article.

ini

i around the circumference if desired.

.i When applying the internal coating by Ispraying the spray will have to be continued joint.

long enough to till the interior depressions of the corrugatlons at the base line.

The coating might, of course, be applied on the job, but without special equipment for doing this, certain technical ditliculties due to the usual considerable length of the culvcrts, will be presented.

In applying the bands in joining culverts together, it may be desired to pour a small quantity of the coating material into the, cavity/left between .the butted external crois, before the band is tightened up. However, this is not necessary, as the occasional pockets left in the long culverts will lill .up with silt. The .section in Figure 2 shows at 23 a quantity of the bitumen poured into place prior to completing the It will be noted that the filling of the corrugations at the base of the culvert will likewise submerge the internal ledge where one tube section laps another in forming the culvert. Also, if the lap joints made in forming the tube sections from corrugated sheets happen to come at the base of the culvert. which normally is avoided, the coating will submerge this joint also.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is j l. A sheet metal culvert having a lowermost portion formed as a part of a .cylindrical surface corrugated circuniferentially, and an inert, adhesive, plastic substance, free from brittleness when set, substantially filling the depressions of the corrugations of said portion internally thereof over an area confined substantially `to said base, and

'covering the spaces between corrugations so as to present a surface along said base'that is substantially free of depressions, for the purpose described.

i2. A `sheet metal culvert having alowcrmost portion formedas a part'of a cylindrical surface corrugated circumferentially and adapted to expand and contract, and an inert, adhesive, plastic' substance free from brittleness when set, substantially filling the depressions of the corrugations of said portion internally thereof over an area confined substantially to said base, and covering the spaces between corrugations so as to present a, substantially depression free surface along said base, said substance also coating the sidesof the inside of said portion at. least adjacent said filling with aI relatively thin adhesive covering.

'3. A sheet metal culvert having a lower- -most portion formed as part of a cylincovering the spaces between eorrugations so as to present a substantially depression free surface along said base, said substance also coating the sides of the inside of said portion adjacent said iilling with a relatively thin adhesive covering, said substance also being applied as an adhesive coating en the outside walls (if-the said culvert.

4. A sheet' metal culvert havingv a cylindrical body circumferentially corrugated, said body having a coating of soft asphalt, located on the inside thereof at least, covering the lower side walls with a tightly ad herent coating, :tid filling the interior depressions of the corrugations of the culvert over an area confined substantially to said base, and submerging the corrugations and covering the spaces between them se as'to form a substantially depression free floor lengthwise of the culvert.

5. A sheet metal culvert comprising a plurality of sections secured together end to end, each section having a cylindrical body circumferentially corrugated, said body having a coating' of soft asphalt or its equivalent, located on the inside thereof at least, covering the lower side walls with a tightly adherent coating, and filling the interior depressions of the corrugations of the culvert, over an area confined substantially to said base, and submerging lthe corrugations and covering the spaces between them so as to form a substantially depression free floor lengthwise of the culvert.

6. A sheet metal culvert having a cylindrical body circumferentially corrugated, said body having a coating of soft asphalt, located on the inside thereof, coveringthe lower -side wallswith a tightlyI adherent coating, and filling the interior depressions of thecorrugations of the culvert over an area confined substantially to said base, with a 'body that substantially submerges the corrugations, covers the spaces between them, and forms a depression free floor lengthwise of the culvert, said coating material also coating the exterior of the culvert with a relatively vthin covering. j

7. A corrugated metal culvert having on its interior adjacent the bottom a coating of adhesive non-brittle material resistant te abrasion, said material at the bottom of the culvert filling the interior depressions of the corrugations over an area confined substantially to said bottom and covering the space between the depressions so as to form a substantially depressionfree surface te resist abrasion and corrosion ofthe corrugated bottom by materials passing through the culvert.

8. A corrugated metal culvert having the interior depressions of its bottom corrugations substantially filled and the .spaces between them covered with an adhesive 'abrasion-resisting material tenaciously adhering to the culvert bottom over an area confined substantially to the culvert bottom to form a surface substantially free from depressions so as to prevent abrasion of the culvert bottom by materials lpassing therethrough.

9. A corrugated sheet metal culvert comprising a plurality of cylindrical sections secured end to end, the valleys and crests of the corrugations in eachsection extending circumferentially, the lower portions of the inner surface of said culvert being coated with an adhesive flexible substance of abrasion-resisting nature, a portion of said coating substance substantially filling t-he interior depressions of the corrugations and covering the spaces between them over an arca confined substantially to the base of the culvert to provide a substantially depression free surface in the bottom of the culvert to prevent abrasion by materials passing therethrough.

10. A corrugated sheet metal culvert comprising a plurality of cylindrical sections secured end to end, the valleys and crests vof the corrugations in each section extending circumferentially, the lower portion of the inner surface of said culvert being coated with an adhesive flexible substance ofabrasion-resisting natures, and a portion of said coating substance substantially filling the interior depressions of 'the corrugations and covering the spaces between them over an p area confined substantially to the base of the culvert, to provide a substantially depression free surface in the bottom of the culvert to prevent abrasion by materials passing therethrou h, and filling and covering any joints in oretween the seetions,'occurring along the base portion of the culvert.

1l. A sheet metal culvert having its lowermost portion formed as an are shaped surface corrugated circumferentially to expand and contract under different strains and climatic conditions, and an inert adhesive plastic substance, substantially filling the valleys of the corrugatons along the base and confined substantially to the base of said portion internally thereof, and covering the spaces between valleys thus presenting sub- Stantially an uncorrugated4 surface along said base, said filling possessing a sufficient degree of `expansion and-contraction so as to practically synchronously respond to the expansion and contraction of said lower portion, thereby preventing disruption of the filling and separation of the filllng from the said portion internally thereof and cover-l ing the spaces between them over an area confined substantially to the base so as to present a surface along said base, that 'is` substantially free of depressions and a film of paint-like nature extending upwardly along the inside of the culvert as a continuation of the filling.

13. A circumferentially corrugated culvert having the interior thereof atleast coated with an adhesive, resilient substance covering atleast a substantial portion of the lower half of the culvert, but so applied along the base of the culvert as to be substantially thicker than as applied to the side walls.

14. A sheet metal culvert or the like having a cylindrical body corrugated circumferentially, and hence transversely to its length, and a coating within the said body of a closely adherent, resilient bituminous material of asphaltic nature, said coating being applied as a paint-like protective'fihn to a lower portion of thebody at least, but substantially filling the corrugations along the base of the body lengthwise thereof as if to a liquid level reaching to the crests of the corrugations and covering them, thereby providing a substantially level floor along the base of the culvert exclusively, as and for the purpose described.

15. A sheet metal culvert or the like having a galvanized cylindrical body corrugated circumferentially, and hence transversely to its length, and a coating within the said body of a closel adherent, resilientbituminous material o asphaltic nature, said coating being applied as a paint-like protective film to a lower portion of the body at least, but substantially filling the corrugations along the base ofthe body lengthwise thereof, as if to a liquid level reaching to the crests of the corrugations and covering them thereby providing a substantially level floor along the base of the culvert exclusively, as and for the purpose described.

i l ALLERTON S. CUSHMAN. 

